Opera and Internet Explorer 9 browsers don’t provide CSS 3D transformations support. If you are playing your HTML5 presentation in one of these browsers, 3D transition effects will be replaced with similar 2D effects. (Learn more)

When you are creating your PowerPoint presentation on Windows OS, styles (i.e. bold, italic) for certain fonts are generated by the OS itself. In this case, the styles of these fonts will not be preserved when your HTML5 presentation is played on an iPad, since iOS can’t reproduce these styles.

The issue occurs because iOS of your iPad uses a so-called ‘singleton’ media player. This means that you can't play audio and video together, or several audio and video files simultaneously. Say, you launch a video file while audio is still playing. In this case audio playback will be stopped.